procsedixgs of the polytechnic association. 1057 



Solar Gaseous Spectrum, 

 Mr. Korman Lockjer first proposed a plan for detecting the gase- 

 ous spectrum of the sun, without the intervention of an opaque bodj, 

 as in the case of an eclipse, to cut off a direct light, but Mr. Gansen, 

 of France, was the first to obtain such spectrum under the direct light 

 of the sun. Mr. Lockyer, two months later, did the same thing, and 

 found a gaseous spectrum of a certain height, present at all points, 

 and hence concludes that an enveloj) of luminous gas surrounds the 

 sun, to a distance of about 5,000 miles, while the luminous promi- 

 nences are only accumulations of the same gaseous matter, reaching 

 sometimes to the height of 70,000 miles. 



The Opiithaxmos. 



This instrument, invented by the Rev. John A. Scott, of Morefield, 

 \Yest Virginia, is an automatic photographic camera, "srhich is ele- 

 vated by means of a small balloon, and held at the required height by 

 a cord, until a picture of the landscape below is taken. The camera 

 hangs in a vertical position, and contains a sensitized plate, which, 

 after having its focus adjusted, is elevated and exposed l)y means of 

 clock-work, so arranged as to operate precisely at the moment when 

 required, when the pljfte is again covered by an automatic action and 

 the palloon is drawn down. Within the camera is a magnetic needle, 

 which is arrested, on a graduated circle, by means of a wire net-work, 

 at the instant the plate is exposed, and thus is indicated the magnetic 

 meridian of the place represented in the picture. The truthfulness 

 and minuteness of detail thus obtained, makes this ingenious photo- 

 graphic arrangement preferable to the old photographical method, 

 which, from the time and labor required for actual surveys, is by far 

 the most costly. 



Wire Tbam^wats. 



At Bardon Hill Quarries, neai' Leicester, England, a new kind of 

 tramway is in successful operation. It is about three miles in length 

 and consists of an endless line of wire rope, which is elevated and 

 passes over one set of rollers, each roller being sustained by a pole, 

 and returns by another set of rollers and poles. At one end the wire 

 passes over a clipped drum, which is moved by a steam engine,. 

 Boxes- in which goods are to be carried, are suspended from the rope,, 

 and so arranged with suitable grooves in the hooks by which the 

 boxes are held, that the latter are prevented from coming in contact 



[Inst.] 67 



